detect runtime modification of post handlers

3 files changed, 25 insertions, 0 deletions

diff --git a/php_suhosin.h b/php_suhosin.h
index 93a6b45..1e2e053 100644
--- a/php_suhosin.h
+++ b/php_suhosin.h
@@ -307,6 +307,7 @@ char *suhosin_decrypt_string(char *str, int padded_len, char *var, int vlen, cha
 char *suhosin_generate_key(char *key, zend_bool ua, zend_bool dr, long raddr, char *cryptkey TSRMLS_DC);
 char *suhosin_cookie_decryptor(TSRMLS_D);
 void suhosin_hook_post_handlers(TSRMLS_D);
+void suhosin_unhook_post_handlers();
 void suhosin_hook_register_server_variables();
 void suhosin_hook_header_handler();
 void suhosin_unhook_header_handler();
diff --git a/post_handler.c b/post_handler.c
index c36c1a0..c097a06 100644
--- a/post_handler.c
+++ b/post_handler.c
@@ -79,6 +79,14 @@ last_value:
     }
 }
 
+static void suhosin_post_handler_modification(sapi_post_entry *spe)
+{
+        char *content_type = estrndup(spe->content_type, spe->content_type_len);
+        suhosin_log(S_VARS, "some extension replaces the POST handler for %s - Suhosin's protection will be incomplete", content_type);
+        efree(content_type);
+}
+
+
 /* {{{ php_post_entries[]
  */
 static sapi_post_entry suhosin_post_entries[] = {
@@ -90,6 +98,8 @@ static sapi_post_entry suhosin_post_entries[] = {
 
 void suhosin_hook_post_handlers(TSRMLS_D)
 {
+        HashTable tempht;
+        
 #if PHP_MAJOR_VERSION > 5 || (PHP_MAJOR_VERSION == 5 && PHP_MINOR_VERSION > 0)
         sapi_unregister_post_entry(&suhosin_post_entries[0] TSRMLS_CC);
         sapi_unregister_post_entry(&suhosin_post_entries[1] TSRMLS_CC);
@@ -99,8 +109,21 @@ void suhosin_hook_post_handlers(TSRMLS_D)
         sapi_unregister_post_entry(&suhosin_post_entries[1]);
         sapi_register_post_entries(suhosin_post_entries);
 #endif
+        /* we want to get notified if another extension deregisters the suhosin post handlers */
+
+        /* we need to tell suhosin patch that there is a new valid destructor */
+        /* therefore we have create HashTable that has this destructor */
+        zend_hash_init(&tempht, 0, NULL, suhosin_post_handler_modification, 0);
+        zend_hash_destroy(&tempht);
+        /* And now we can overwrite the destructor for post entries */
+        SG(known_post_content_types).pDestructor = suhosin_post_handler_modification;
 }
 
+void suhosin_unhook_post_handlers()
+{
+        /* Restore to an empty destructor */
+        SG(known_post_content_types).pDestructor = NULL;
+}
 
 /*
  * Local variables:
diff --git a/suhosin.c b/suhosin.c
index 1b54c39..e111d55 100644
--- a/suhosin.c
+++ b/suhosin.c
@@ -191,6 +191,7 @@ static void suhosin_shutdown(zend_extension *extension)
 {
         suhosin_unhook_execute();
         suhosin_unhook_header_handler();
+        suhosin_unhook_post_handlers();
     
     if (ze != NULL) {
             ze->startup = orig_module_startup;